From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 58752C76196 for ; Fri, 19 Jul 2019 04:16:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2E45E21851 for ; Fri, 19 Jul 2019 04:16:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563509765; bh=oYIQvlnEexFzb5pTQnlQ/wNvAiQGVeR9MTJSCX6Iqbw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=o3IZ2xVZB+zza/n/vs5YPTSdtC5kpRNM4grSqz7kLpadCO5oz7wERjyTQ6uwGH+o5 chDjCjjpijMCwe30M9xrYaGaBAOrvajaVI+Xv7AFPZ6ZJGVVls1z2TvgPh280QMKmP 1bmEWa5XJ8B7O1TeZiLEqpjt+x6MMJiqSyEO1DOk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727497AbfGSEQE (ORCPT ); Fri, 19 Jul 2019 00:16:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:51912 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388855AbfGSEPd (ORCPT ); Fri, 19 Jul 2019 00:15:33 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A9F4F2189D; Fri, 19 Jul 2019 04:15:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563509733; bh=oYIQvlnEexFzb5pTQnlQ/wNvAiQGVeR9MTJSCX6Iqbw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=i76q64kSvgx5aNvJCjNPBKV0c4eCxQJ8nGHNWpCLwCylcQvetuWluvMY/vrdWbVGN IfbEOw44FssIHQCLFqKUt30PnhFqDuBDe/yGXIkn8XI+Lo2ytquIULsrzlyyS3DSUg mL73+RSXdtUgfZI5ePyXwGwiBh6MeC0dynJAMwIY= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Yuyang Du , Qian Cai , Peter Zijlstra , Andrew Morton , Linus Torvalds , "Paul E . McKenney" , Thomas Gleixner , Will Deacon , arnd@arndb.de, frederic@kernel.org, Ingo Molnar , Sasha Levin Subject: [PATCH AUTOSEL 4.4 35/35] locking/lockdep: Fix lock used or unused stats error Date: Fri, 19 Jul 2019 00:14:23 -0400 Message-Id: <20190719041423.19322-35-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190719041423.19322-1-sashal@kernel.org> References: <20190719041423.19322-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Yuyang Du [ Upstream commit 68d41d8c94a31dfb8233ab90b9baf41a2ed2da68 ] The stats variable nr_unused_locks is incremented every time a new lock class is register and decremented when the lock is first used in __lock_acquire(). And after all, it is shown and checked in lockdep_stats. However, under configurations that either CONFIG_TRACE_IRQFLAGS or CONFIG_PROVE_LOCKING is not defined: The commit: 091806515124b20 ("locking/lockdep: Consolidate lock usage bit initialization") missed marking the LOCK_USED flag at IRQ usage initialization because as mark_usage() is not called. And the commit: 886532aee3cd42d ("locking/lockdep: Move mark_lock() inside CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING") further made mark_lock() not defined such that the LOCK_USED cannot be marked at all when the lock is first acquired. As a result, we fix this by not showing and checking the stats under such configurations for lockdep_stats. Reported-by: Qian Cai Signed-off-by: Yuyang Du Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Will Deacon Cc: arnd@arndb.de Cc: frederic@kernel.org Link: https://lkml.kernel.org/r/20190709101522.9117-1-duyuyang@gmail.com Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin --- kernel/locking/lockdep_proc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c index dbb61a302548..9778b6701019 100644 --- a/kernel/locking/lockdep_proc.c +++ b/kernel/locking/lockdep_proc.c @@ -227,6 +227,7 @@ static int lockdep_stats_show(struct seq_file *m, void *v) nr_hardirq_read_safe = 0, nr_hardirq_read_unsafe = 0, sum_forward_deps = 0; +#ifdef CONFIG_PROVE_LOCKING list_for_each_entry(class, &all_lock_classes, lock_entry) { if (class->usage_mask == 0) @@ -258,12 +259,12 @@ static int lockdep_stats_show(struct seq_file *m, void *v) if (class->usage_mask & LOCKF_ENABLED_HARDIRQ_READ) nr_hardirq_read_unsafe++; -#ifdef CONFIG_PROVE_LOCKING sum_forward_deps += lockdep_count_forward_deps(class); -#endif } #ifdef CONFIG_DEBUG_LOCKDEP DEBUG_LOCKS_WARN_ON(debug_atomic_read(nr_unused_locks) != nr_unused); +#endif + #endif seq_printf(m, " lock-classes: %11lu [max: %lu]\n", nr_lock_classes, MAX_LOCKDEP_KEYS); -- 2.20.1